Such customarily used lines and line connectors are known from WO 2009/053227 A1. For example, they are used in automotive technology, in particular with Diesel engines in so-called SCR catalytic converter systems (SCR=selective catalytic reduction), wherein an aqueous solution, for example, 32.5% urea solution is used as NOx reducing agent. At the same time, it involves the well-known problem that because of its freezing point of approximately −11° C. such urea-water solution requires special measures to prevent freezing in the event of low ambient temperatures, in order to ensure that the SCR catalyst is functioning even at low ambient temperatures.
When pipe-in-pipe applications are used in connection with media that are not allowed to mix a specific separation of both circuits has to be provided. For example, a firmly bonded connection is produced by means of laser welding. To produce a welded connection, in particular by means of laser welding, free access to the connection area is required. This presents a problem especially when connecting the inner pipe with the connecting elements of the line connector, especially when the outer pipe consists of a material that cannot be compressed in axial direction, or only to a certain extent.